Mountain of Greatness – DVP # 7

Few volcanoes on the planet represent such an awesome sight as the majestic Mount Cameroon. It stretches from the edge of the Atlantic at Bakingili Beach and reaches an astounding height of 4040 meters. Due to its prominence it is regularly dusted with snow at the top.

Mount Cameroon, or as I am used to calling it, Mount Fako, is the only volcano to date that I have worked professionally with as a geophysicist. As volcanoes go it is somewhat of a “terra incognita”, and to be quite frank, most that has been written about the volcano is just not correct. So, there is an ample chance here to set a few things straight, do some real science, and also put the limelight on one of those volcanoes of the world that is both highly dangerous and completely unmonitored.

Geologic setting

To understand Mount Fako we first must start with the geologic setting, and also come to terms with the geologic timescale of West African Volcanism. There are 3 distinct geological features that we need to contend with as we speak about Mount Fako.

The Cameroon Volcanic Line

Mount Manengouba Caldera.

The first one is the Cameroon Volcanic Line, it consists of 4 volcanic Islands, 2 large seamounts, Mount Fako itself, Manengouba, Bambouto, The Western Highland with Mount Oku, Ngaoundere, Mandara and Biu. Volcanism in the Cameroon Volcanic Line spans a time period of 49 million years and contains two distinct periods.

The first period consists of magmatic domes and maars, most of them are heavily eroded today and requires specialized knowledge to find. This period ended about 33 million years ago and can be seen as a proto-volcanic phase.

View from inside the caldera of Mount Bamboutos. Do note the phonolitic plug.

The second period started 32 million years ago at Mandara and Mount Oku. The ensuing volcanism is highly programmatic and follows a pattern where the volcanoes are born through large scale basalt eruptions creating layers between 50 and 600 meters thick. After that comes a period of trachytic lava with minor rhyolitic ignimbrites, after that comes a large caldera event with subsequent dyke formations and phreatomagmatic eruptions of diminutive scale.

The eruptive phases of the volcanoes spans from millions of years to tens of millions of years. There is no good explanation to why the basaltic eruptions during a fairly short time switch to highly explosive volcanism. My suggestions is that the large basalt flows necessitate large volume magma reservoirs that over time fills with residue from earlier eruptions and also that the magma reservoirs becomes inundated with stale base rock low in volatiles.

Mount Oku with the caldera lake.

The formation of Cameroon Volcanic Line has erroneously been attributed to a hotspot or mantleplume. And to the naked eye there seems to be a telltale track of volcanic islands and volcanoes. There is just a problem, there is definitely no hotspot or mantleplume to be had. I will though get back to this later on.

Let us start at the Northeast and work our way down to Mount Fako. The first volcano we stumble upon is Biu, very little is known about the volcano except that it morphologically follows the normal composition for a CVL volcano and that is started its activity less than five million years ago.

Mount Ngaoundere with one of the for the Cameroon Volcanic Line so common phonolitic plugs.

To the southeast comes the 32 million year old volcano of Mandara with an unstudied volcano due south. Further southeast of that unstudied volcano is the massive caldera of Nagoundere.

The group above is a distinct group of its own, not due to being morphologically different; instead they sit on a different rift system than the rest of the volcanoes. This rift system is roughly horseshoe shaped and transects the Central African Shear Zone that is home to the volcanoes below.

Annobón Island, a real tropical paradise where you can get down and dirty with your phonolite plugs.

Now it is time to continue with the Western Highlands that consists of two main volcanoes. The northernmost of those is Mount Oku that was active 31 to 22 million years ago before it went caldera forming Lake Oku. Southwest of Mount Oku we find the massive caldera of Bambouto that was active between 21 and 14 million years ago.

Next in line is the 1 million year old active volcano of Manengouba that is situated northeast of Mount Fako. It is a part of the Fako volcanic zone but is a younger and distinctly separate volcano. What makes Manengouba so interesting is that it took less than 1 million years before it went caldera.

Now it is time to get really serious with the plugs. Pico Cão Grande on Sao Tomé.

If we for now skip Mount Fako itself and jump to the other end of the CVL we find the miniscule volcanic island of Annobón and its volcano Pagalu. This diminutive Island formed during an unusually short volcanic period that started 5 million years ago and lasted less than 1 million years.

Next in line is Sao Tomé that is one large shield volcano. It started to form 13 million years ago and the volcano is still believed to be active due to the young cinder cones situated on the southeast side of the island. It is also well known for the Pico Cão Grande volcanic monolith.

Beutifal shield crater lake with a shield in the background. Pico Basile volcano on Bioko Island.

To the northeast of Sao Tomé we find the island of Principe that erupted from 31 million years ago to 14.7 million years ago.

The next island is Bioko that is housing no less than 3 major shield volcanoes that have been active historically. Volcanism here started 1 million years ago and eruptions occurred last in the 19th century.

Central African Shear Zone

All of the volcanoes from Pagalu up to that peskily unstudied volcano is situated on the CASZ, through that unstudied volcano runs the previously mentioned horseshoe shaped fault zone.

The CASZ formed around 640 million years ago and was volcanically active around that period. Previously western scientists believed that the CASZ was tectonically inactive until an M5 earthquake occurred and was monitored on a temporary seismometer. Local sources have though always stated that large earthquakes happen frequently along the shear zone, especially during eruptive phases where houses commonly have been leveled by the intense seismic activity.

The Cameroon Volcanic Line showing the CVL, the CASZ and the Benue Through. Also visible is the horseshaped fault zone. Image taken from “The Cameroon Volcanic Line Revisited:Petrogenesis of Continental Basaltic Magmasfrom Lithospheric and AsthenosphericMantle Sources” by Marzoli et al.

The CASZ was volcanically active both 640 million years ago and also 130 million years ago during the break up of Pangea. One should note that the 3 active periods do not rule out smaller scale volcanism in between. As such the CASZ is the oldest volcanic feature on the planet that is still active.

The CASZ used to continue in the form of the Pernambuco Fault in Brazil, but as some people have noticed, the breakup of Pangea occurred and the Shear Zone ended up divided across two continents by a sizeable ocean.

Benue Through

Eruption of Cameroon in 2000. Private photograph taken from Buea.

At the same time as the single largest eruptive episode started at Paraná-Etendeka with both trap formations and the largest explosive eruptions on record the West African Craton and the Congo Craton started to separate at what is today the Benue Through.

Volcanism at Benue Through started prior to the Paraná-Etendeka event at 149 million years ago and continued for roughly 100 million years.

As the breakup of Pangea was completed the Benue Through separation of Cratons reversed and the Through started to close up, that created a heavily folded zone adjacent to the CASZ. I would seriously try to remember this feature in your mind as I get back to the hotspot and mantleplume issue.

The Hotspot

The reigning theory for the volcanism on the Cameroon Volcanic Line is that it is created by a hotspot that is travelling in an ENE direction. Only problem is that the time record does not support this at all. To be quite frank, the pattern of age of the volcanic centers is entirely random. Let us repeat the ages from north to south. 5, 32, unknown, 11, 31, 21, 1, 3, 1, 31, 14 and 5. Either I have grown dimwitted or there is just not any time sequence that is associated with a hotspot track 1 600 kilometers long.

Tomographic map of 25km depth. Do note the position of the African Superplume and keep track of it. No Visible signs of a hotspot here at CVL. Image made by DownUnder for Volcanocafé.

Some have tried to save this by surmising that there is another hotspot there and they also favor to put in influence from the Saint Helena Hotspot in the mix. It still does not blend very well with reality.

So, if the time does not indicate a hotspot, what does? Well, the temperature of the erupted magmas is quite enigmatic. The volcanoes have erupted varied temperature magmas with the heat record at 1 338C and the coldest at 1 106C with a medium temperature of 1 280. That would put it at 220C below the temperature of the Hawai’i hotspot and en par with the Icelandic Hotspot. As such that would be a fairly cold hotspot, but those exist as we know from Iceland.

Tomographic map of 75km depth. Do note the position of the African Superplume and keep track of it, also note how cold the two cratons are. No Visible signs of a hotspot here at CVL. Image made by DownUnder for Volcanocafé.

Only problem is that the hotspots of Iceland, Hawai’i and the African Plume are caused by upwelling from deep within earth and all 3 of those are clearly visible when you create tomographic charts of the mantle.

A tomographic chart shows anomalies in the speed at which sound travels after an earthquake. The most clearly visible such entities are the Icelandic Hotspot and plume upwelling and the African Plume residing under Eastern Africa. Those can be seen very deep indeed.

Tomographic map of 125km depth. Do note the position of the African Superplume and keep track of it. No Visible signs of a hotspot here at CVL. Image made by DownUnder for Volcanocafé.

Problem is just that if we go and look at the CVL we see nothing as such, actually we even find inverse anomalies at depth showing the area to be slightly cooler than expected.

The next theory is that the Benue Through is causing a localized upwelling of material from below the LAB (Lithosphere-Asthenosphere Boundary). Only problem is that this is not evident from the tomographic maps either.

Tomographic map of 200km depth. Do note the position of the African Superplume and keep track of it. No Visible signs of a hotspot here at CVL. Image made by DownUnder for Volcanocafé.

This leaves us with a conundrum. We only know that there is no hotspot causing the volcanism. We also know that the volcanism is extremely extended in time.

Volcanism is caused either by hotspots, spreading rifts like the MAR or subduction caused melt. We know that for about 50 million years there was spreading rift volcanism going on adjacent to the CVL at the Benue Through, we also know that this started after the CASZ volcanism. We also know that there historically has been no subduction going on there. Sooner or later subduction in the area will start, but we are not there quite yet geologically speaking.

Tomographic map of 300km depth. Do note the position of the African Superplume and keep track of it. No Visible signs of a hotspot here at CVL, instead the temperature is below average at the litosphere/adenosphere boundary, definitely not a Mantleplume nor a hotspot there. Image made by DownUnder for Volcanocafé.

We are here left with a 640 million year old riddle regarding volcanism. Either we are missing something, or we have a fourth form of volcanism going on at the CVL. Sadly the CVL and Mount Fako is highly understudied. This is the first reason that Mount Fako should be on the new Decade Volcano Program.

Mount Fako

Even though it is sited as being a stratovolcano Mount Fako is actually a fissure row of volcanic craters. In some respects it reminds of an effusive cousin of Iceland’s Hekla volcano in shape. Eruptions at the volcanic fissure line started 3 million years ago with large scale basalt flows that built up an elongated shield. As volcanism continued with shorter lava flows the sides have grown increasingly steeper until a steep sided elongated hull like shape formed.

As volcanism progressed the lava flows has grown increasingly volatile rich and eruptions often take place at 2 or more places. One of the sites will be high up on the volcano and will be explosive in nature and further down the fissure there will be an entirely effusive eruption causing lava flows that often reach down to the Atlantic Ocean.

The eruptions span between VEI-2 and VEI-4 with VEI-2 sized eruptions being the by far most common type.

During eruptions the volcano becomes highly seismic with extensive and intense earthquake activity that often affects the capital of the Southwest Region Buea heavily with raised houses and deaths occurring. Normally residents of Buea are forced to sleep outdoors during eruptions to not risk that their houses cave in on them.

The lavas erupted are bimodal with basalts as the main component, but the other component are trachytes and phonolites signifying a volcano containing more evolved lavas in an intermediary stage. The sheer size of the 1 400 cubic kilometer volcano, the unstable flanks and the evolving magmas, point to a volcano nearing its end stage.

If we compare Mount Fako to its post caldera brethren to the northeast we can see that they reached about the same size before they went caldera. The volcano does though not yet hold evolved enough magmas to form ignimbrite flows.

The main forms of hazard are through seismicity and flank collapses. For flank collapses the cities of Buea and Limbé are in the strike distance. The gravest danger of this volcano is though not through an explosive eruption.

Instead the gravest risk is that a large basalt flood event will occur like the one that was potentially witnessed by Hanno the Navigator 450 BC. Another large effusive eruption would not kill people directly, instead gas content and destruction of cities and farms would cause the death toll.

Mount Fako is today not monitored at all. There is no active Seismometer, no GPS, no Inclinometer. Instead the park rangers are tasked with observing what is going on visually and forward the information to anyone interested in knowing it.

Together with the risk to the large local population and the scientific conundrum that Mount Fako poses it clearly merits to be placed at place number 7 on our proposed new Decade Volcano Program.

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118 thoughts on “Mountain of Greatness – DVP # 7”

Thank you Carl. This is an area of the world that I have not even looked at as far as Volcanoes are concerned. So yes! This IS a dangerous volcano in that as Carl says it is not monitored at all.
So much new information for me here. I need to go away and study this area for myself…. I’ll be back if I can find any more information, links or Images…It’s too hot to do house and garden chores anyway …..:D (I use any excuse to go Volcano hunting rather than work :D)

Thank you for the update! As long-time readers might remember I was brought up in the British Cameroons (which tells you how long ago that was) by Mount Cameroon at Bota (by the sea) and Tiko (a little bit inland). Both of them are near what is now called Limbe but was then called Victoria. It was a fabulous childhood and probably why I’ve always loved volcanoes!

I’m off on a very short holiday to Skye – so will not be volcano watching until about Wednesday or Thursday next week. 🙂

Welcome to Skye, if you get anywhere near Ullinish on the west side please drop in at Sleepy Hollow at the bottom of a track leading from the Ullinish Lodge. It’s a lovely walk from us down to the Island of Oronsay and it’s terminal sea cliff. Kettle will be on.

I love to read the posts on your site; however on the subject on this particular region I am a bit confused how this is included in your DVP. The region is huge and has a large rift system and there is potential for something major here. I know people have lost their lives to asphyxiation( please correct me if I am wrong) around the area. But surely the impact around the region it is going to have is low. I am probably completely wrong in this matter and going to be shot down in flames.

I believe that the “rules” for this series are that the Volcanoes involved have the potential for widespread deaths, not necessarily just in the immediate region. A large scale flood basalt eruption would release a HUGE amount of gas and this would have the potential for far-reaching devastation to large swathes of the southern hemisphere.

When Laki erupted in 1783 releasing around 14.7 km3 of basaltic lava, the gas (sulphur dioxide)released caused a large amount of crop failures and famine across Europe and the northern hemisphere, and killed over 10,000 (22%) of the Icelandic population at the time and caused a noticeable dip in global temperature for that period which is found in tree ring records.
(source: http://www.wired.com/2013/06/local-and-global-impacts-1793-laki-eruption-iceland/)

The Laki event would be considered TINY when compared to a large flood-basalt eruption such as the Decca Traps(512,000 km3) or the Siberian Traps (The original volume of lava is estimated to range from 1 million to 4 million km3.) or even the smallest of the Flood Basalt events the Columbia River(174,300 km3)
(all Wikipedia)

Now given that the global population is much larger now, a flood basalt eruption on a massive scale which Carl suggests (“Instead the gravest risk is that a large basalt flood event will occur like the one that was potentially witnessed by Hanno the Navigator 450 BC. Another large effusive eruption would not kill people directly, instead gas content and destruction of cities and farms would cause the death toll.”) might be possible in this region, would have GLOBAL consequences.

There is even evidence to link Flood Basalt events to mass extinction events and even a small one would have a catastrophic impact in the region and globe as a whole.

When reading the article the first thing that came into my head when into my head was a Laki style event but on a larger scale. Much larger !. I would love to know what would cause such a large event. If only I could live a million years to tell the story.

Great article. The point that is being made is based on the potential that this system has. As noted, very little is known, but from the availible data, it’s very capable of doing the very nasty.

I’m currently experiencing a really odd routing issue and can’t get here on my regular pc.

(Geolurking)

For the fellow dakeks. Please do not elevate this log-in to any higher level permissions. I have no idea if the proxy servers are doing man in the middle sniffing. If they do, that would compromise the site.

The 450 BC eruption was not that large – it was a VEI-3 according to the GVP. True flood basalts similar to trap events would not come from mt. Cameroon. You would need a prolific hotspot or extremely rapid rifting to create a flood basalt event similar to ones that have possibly caused extinctions. The only candidates in the world right now for such activity would be in the African rift valley (west africa) or Iceland, which is arguably an active flood basalt event.

With that said, I tend to agree with Ian. The authors did say they welcomed criticism and arguments for this list, so I’ll indulge myself :). For what it’s worth, I enjoyed the post, but I think there was a bit of personal bias here when choosing this volcano. In some fairness, all three volcanoes so far on this list have been written about by Carl before, but I would say that the first two are definitely deserving candidates.

I would have to imagine there are many more that are better candidates for a large catastrophe in the next
100 or so years. Even a volcano like Etna would be a better candidate based on the fact that it has a higher local population and a fairly similar eruptive style to Cameroon. Also, Etna has had known and larger slope failures, as well as caldera events, both of which would be much more catastrophic than anything that could potentially occur at Cameroon.

Even in the event of a catastrophic slope failure on Mt. Fako, the cities nearby aren’t THAT large (not close to 1 million population), and Mt. Cameroon isn’t likely to go caldera in the near future.

With that said, this was an interesting post on an interesting volcano.

You are perfectly entitled to, and indeed welcome 🙂 , to criticise our choices, but please let me put a few facts in perspective here!

First of all I’d like to point out that our selections were not exclusively based on the MDE criterion being met. Some of the criteria of the IAVCEI project still remain such as increasing understanding and knowledge. As Carl points out, the entire CVL is poorly studied, if at all. The modus operandi is confusing and not understood at all. This being the case, we cannot apply what we know from studies of other volcanoes in a completely different geological and volcanological context.

Furthermore, there are several calderas in the immediate vicinity. How and when did they come into existence? Can we guarantee that Mt Cameroon is not a candidate in the near geological future without any knowledge of how she works?

If we do compare with what we know of other volcanoes, Mt Cameroon has a prominence of no less than 3,901 m, which means there are precious few volcanoes in the world with a greater prominence. Any volcano with such a great edifice is a candidate for a flank collapse (which should not be confused with either lateral blast or flank eruption) as well as a summit/caldera collapse induced by a major eruption.

And if we do compare with Etna, let me point out that Etna is monitored 24 hours a day by volcanologists working shifts who have access to a host of real-time information on computer screens in a warm office. The Cameroon Park rangers have no relevant training, have access only to “Eyeballs Mk.Ia” and “Eardrums v 1.0” instrumentation. Communications? If working, telephone landline model 1947.

To sum up, Mt Cameroon is an almost unstudied, completely unmonitered volcano which seems to operate on principles different from all other known (eg. studied) volcanoes. It is located in a very poor, African country, a fact that should not disqualify the people threatened from being afforded the luxuries we take for granted such as adequate study, monitoring and hazard/emergency planning.

That said, of course there are volcanoes at least as dangerous that we have deliberately not entered into our list. If there indeed is a bias here, I share it as co-author of this series. 🙂

I agree that the 450BC eruption is unlikely to have been very large. Really big volcanic eruptions tend to have noticeable effects on civilisations around the world, reports of strange weather or solar phenomena, failed harvests etc, but there’s nothing really unusual about 450BC to my knowledge. This was the golden age of classical Greece, there are plenty of records available. Certainly if something as massive as a flood basalt eruption had happened there would have been climatic and social consequences around the world.

I think I was using my facebook login when I went to the spam dungeon (are there spam fritters for dinner ?) was just a minor mention that “Benue Through” should be “Benue Trough”
you thought you were too tough to throw in the towel, though you couldn’t truly walk through a trough?

It is really interesting how Cotopaxi constantly huffs and puffs like a train, with frequency in the range of 0.4-1.2hz and 2.5hz. There also appear to be VLP and ULP like events in between the tremors.

I’m not really sure what to make of this. Cotopaxi is seeing some rock fracturing quakes, but still, the predominant quake type has been tremor and long period events. Compared to other seismic events prior to eruptions, I believe we typically see more tornillos and hybrid quakes (aka, poppers). I don’t personally believe that any magma has started to rise through conduits yet. Sure, perhaps some pushing and fracturing above the primary magma chamber has taken place, as it expands but in large part, I don’t think the pressure has built up yet to the point where it’s exceeding the strength of the overlying rock.

With that said, I believe tremor of this type seems to come about when pressure grows inside a closed chamber, when magma degasses, or when magma is moving. Considering the fact that we haven’t seen a ton of poppers, I don’t believe we have seen large volume of magma mobilizing and moving about, at least not yet.

As such, I would personally guess that the seismicity we’re seeing at Cotopaxi right now is coming from a deep injection of juvenile magma into the magmatic system, which is resulting in increased pressure and possible remobilization of older magma. This would account for the high volume of tremor and LP events without the presence of sharp, higher magnitude quakes. I would assume that if this injection of fresh magma lasts long enough, we’ll no doubt see an eruption. At the same point, if the blob of magma entering the magma system ends, this could easily fizzle as the system cools down and reaches equilibrium.

640 mya predates the formation of Pangea. The cratons, which show clearly in the tomography (blue areas), would not have been in their current positions. They came together around 550 mya. What were the lava types for the earliest known volcanic activity?

The lava types shown above: basalt, trachyte and phonolyte are an interesting mix. Phonolyte is associated with mantle plumes / hotspots. Trachyte is associated with tertiary volcanic activity, e.g the splitting of the North Atlantic.

But this is mainly a grauitous reply to make sure I can still find my way to VC, to thank those who have kept it going, and to commiserate with those who have been particularly badly affected by recent, upsetting events. I had a curious incident last year on the old VC…

Yeah buddy!… no, nothing really great happened, just enjoying the effects of a double vodka martini… specifically because I was able make and consume one without drawing the ire if my wife. (I’m a squid, and an occasional drink tends to make us happy, tho I would have preferred several pints of beer)

But, I can foist my amateur sociological and biological observations and musings on you and be quite happy with it, even if I am dead set wrong. First of all, the name as noted in a discussion with tgmcoy, my actual surname has no direct translation in German, though it is German in origin. Your surname is typically a clue to some skill or job one of your distant ancestors had. In my case, it’s been elusive. No muelers or cooper’s at all. (Miller or people who made barrels – coopers). The closest I have come, is to transliterated it using elder further rumes. It means, “the man who owns the gift of a torch.”

But, this ain’t about me… it’s about the tooth monster… who is half lab… my dog. I picked up a treat for him today, while literally strutting around the grocery store, who took it upon themselves to play Sousa marches on their background music rotation . Sure, they were trying to be pstriotic, but all they needed were to add a few,”ruffles and flourishes ” and they could have completed the nightmare of being stuck in formation for hours at a time in a change of command ceremony.

The doggie treat? Duck jetky. Strip of dried duck. For a part lab, pure nirvana. Probably for the same reason that I have a thing for rye bread.

As for the software, I don’t know. I do know that typically tomographic stuff is done using an inversion process. Rather than calculating what the effects would be on a given input signal, you take the end-product and to a reverse calculation as to what would have caused it to look the way it does. Its a more refined thing that you and I were doing with El Heirro seismic data where we were inferring the slow areas/paths in the crust under El Hierro based on how fast the signals should have traveled, vs what we were seeing from the instruments. My math brain petered out on me at about that time and I felt that GPS uplift was giving us a better picture of what was going on rather than some cobbled together not-quite a tomgraphic analysis. Thats how we knew that Sabinosa was sitting on top of a swelling magma pocket when Perez started jumping up and down about “stealing” proprietary data placed on a public web page. That he later went in and feathered his “resume” by getting in on a paper that admitted an eruptive event further to the west of the island reveals his true lack of integrity. He should have warned people away from Sabinosa since they were sitting directly on top of an old scoria cone that was directly over a swelling chamber. He could have gotten a lot of people killed with his arrogance. He and they got lucky.

After some weirdness trying to set up my avatar (not successful), I’ve finally managed to get to the new VC forum.
With both the ongoing and expected volcanic activity in the near future, getting VC up and running smoothly is a must for both those both in harms way and those with vested interests (such as public safety) when dealing with volcanic events. As we’ve seen in the past, VC has served well as a trusted resource for hard data/information, while still providing an open-format discussion/dialog. Well done in getting this site up and running so quickly. (old name: C.Heden)

Retrieved from Limbo – first time reactions always do end up there, after approving one, it should be fine. /Lugh

Local grocery store has been playing Sousa Marches on the internal store background music system. I take it as an attempt to get people into the spirit of buying stuff for the 4th of July. I have to admit that it does give you the desire to walk briskly up and down the aisles. All they really needed was to add “ruffles and flourishes” and they could have completed the nightmare of standing in formation for hours on end waiting for the change of command ceremony to complete so you could get some water to relieve the oppressive heat standing out there on the deck…

@Carl – Fantastic article. I am going to probably be in the KarenZ camp with regards to the system being along the suture line of two ancient cratons. Any idea if this could just be the weakest route for “blobules” of magma from the African superswell?

And at DownUnder → I reiterate what I stated in my phone persona/login. Great plot work!

We know this is probably tension accumulated at the eastern part of the SISZ; which is ripe for a M6.5.
The IM spoke about this last month.

So we should watch out anything beyween Reykjanes to Hekla… Bláfjoll is another area of tension… and Reykjanes we already know it had volcano-tectonic movements… As the volcano was put in yellow alert some days ago

I noted that one too Irpsit, and how it runs from the WVZ (Hengill) to Vatnafjöll, the last 40 km almost ruler straight through the SISZ. If you have a rifting event at Bardbarbunga and one at Reykjanes, is it a wonder that the SISZ (South Iceland Seismic Zone) is active?

In connection with his favourite volcano, Carl has often pointed to volcanism shifting from Vatnafjöll to (form) Hekla, so this line of earthquakes is doubly interesting.

To add 3D tomography, there is a possible basalt flow under CVL, as can be seen also in my 2D tomography images above, and as some have speculated, could be from where magma uplifts.
The vertical scale is largely increased to give better appearence. Data, like the graphics above, is from the S2.9EA global dataset.
These 3 plots are the same, just under a different angle of view and in different color (just some testing along the way). The E African plume is also visible and the MAR channel.

Haha a shark LOL 😀
Its not tomography. This is simple underwater terrain, aka Bathymetry (underwater topography). It is how this terrain would look like if you would remove the water. This is Voring basin,NW off the coast of Norway.

unfortunately the loop has moved on from the activity (which I didnt realize it would do or I’d have screen grabbed it), but there was a “puff” of something from the summit, looked unrelated to the cloud movement

My PW is based on google acct. Will word press recognize the change and allow log in if necessary.

Thanks for the suggestion. It is not about remembering the new PW, which I do have problems with, (: – o) but I am a little confused if the change will be noted and accepted by Word Press. Maybe I am not very clear. I have had this problem elsewhere where my next to last PW was recognized but not my newest one.

We are developing the habit of changing PW rather frequently. To many lurkers around (no offense meant GL, lol).

i *think* that if you’re using your google account to sign in for commenting, then it *should* remember the change. If you have any issues signing in, drop us an email to volcanocafe.org@gmail.com and we can help sort you out.

Thanks for the great work, DownUnder. I’ve taken one of your images and overlaid the approx. location of other notable volcanoes in the region that are not associated with a tectonic rift. Makes you wonder if Carl has something. btw, I’ve spent some time in the savannas of central Africa and there are lots of, what looked to me, phonolite plugs.

Today I don’t think there’s much volcanic research going on near one of the more active ones( in Darfur, Sudan).

Yes, I am biased of course. It is very hard to not be biased about a volcano like this. Both scientificaly and emotionaly.
It does though merrit the spot due to the lack of scientific research, the longevity of the regional volcanism, and due to the risk it poses for the local residents.
As some have pointed out, there are numerous large calderas, and all of them have produced ignimbrite flows, many of them multilayered ignimbrites. It might not be as likely to become a 1MDE volcano in the next 100 years as some on the list, but we had to limit the list a bit.
And we therefore chose one that was unique in many ways, unomonitored and still highly dangerous.
To return to the bias thing. I was not the one who picked this particular volcano, it was Henik who bludgeoned me to do it. In retrospect I think he was correct (as he normaly is).

To return to the subject of this article.
One must remember that even though this volcano has been docile for quite some time it has done large eruption previously. So far it has been mainly lava floods, but the flanks are very steep and several cities are in strike range of a flank colapse. And as mention previously, a majority of the neighbouring volcanoes have gone caldera in a rather nasty fashion.
The thing that I find most scary is that the volcanoes in the region seem to be able to switch rapidly from unevolved magmas to evolved. And with volcanoes of that bulk it is not a nice concept.

It is though a good thing that people criticize the selections we have made. I think that a couple more on the list will evoke comments and differing opinions.
There is a volcano high up on the list that I think will be the greatest surprise of all.

It is good that there is an African volcano in the list. You can argue whether this is the most dangerous one (who knows what else is still to come!) but it points out a continental gap in monitoring. Good job.

Captured this from the latest webcam. Definitely some degassing at the top. I have nothing to compare it against, but it *almost* looks like there is a bit of melted glacier as well. I can’t find a picture of cotopaxi previously, but I would assume this is probably just a dry spot on top of the mountain that wasn’t covered by glacier (that would be a noticeable amount of melt if it had disappeared).

from memory I had this one on my list, I looked for it remembering Goma and found this video, it is scary, and then people are rebuilding/living on its lava flows, humans know he danger but are thinking it has erupted so it will be ok for a while. There is also a new video about Vesuvi and the town of Herc….they didn’t find any body remains like Pompei, they where near the harbor had black marks on bones, from that they found the temp of the flow it is hard to imagine ,

I recently read ‘Pompeii’ by Robert Harris – a lot of it was drawn from Pliny’s observations and it linked back to Strabo’s observations 300 years earlier, but noted that because there had been a long period of repose, it was not known just prior to the eruption that Vesuvius was a volcano, rather than a mountain with earthquakes.